The invention relates to an arrangement for receiving and to a method for handling spent nuclear reactor fuel rods.
In the operation of nuclear reactors in nuclear power plants it is necessary to replace the fuel rods of the fuel assemblies at periodic intervals. The removed fuel rods are taken either to a reprocessing plant or to final storage. Because of the worldwide bottle neck in reprocessing as well as in final storage, it is desirable to keep the cost for intermediate storage as low as possible. This objective can be reached by stacking the fuel rods, packed as densely as possible, in containers which are suitable for the storage as well as for transporting the fuel rods.
A container of this type is disclosed in European Pat. No. 5,623. In that container, which comprises a bottom support and side walls surrounding the fuel rods, a baffle is provided for inserting the fuel rods which has, on its side facing the fuel rods, slots determining the position of the individual fuel rods and against which the introduced fuel rods rest. Disadvantages of this container are that the rods cannot be stored in a densely packed array, e.g., a hexagonal array, because of the thickness of the baffle and that the guiding means for the baffle require stacking of the fuel rods with a pyramid-shaped longitudinal cross-section, so that maximum packing density is not possible either along the transverse or radial dimension or along the longitudinal dimension of the container. In addition to the disadvantage of poor space utilization, such containers have the further disadvantage of inadequate reoval of the decay heat developed by the fuel rods.
An object of the present invention to provide a packing arrangement and container in which these disadvantages are eliminated and with which it is possible to maximize packing density of the fuel rods in the container and at the same time optimize heat removal.